The present invention relates generally to crop harvesting machines, commonly referred to as combines, and, more particularly to providing a mechanism for allowing the header to laterally float in response to the contour of the ground.
Combines, particularly the self-propelled type, are equipped to utilize a variety of crop gathering headers, including headers specifically designed for harvesting corn, cereal grains or soy beans. Normally, these headers are attached to the forward end of the feeder house, which is a structure used to convey crop material from the header to the combine base unit for further harvesting treatment. As is shown in U.S. Pat. No. Re. 26,512, the forward end of the feeder house can be constructed so that the header can be quickly and easily attached thereto. Usually, the feeder house structure is rectangular in shape and includes a rectangular crop inlet opening at the forward end.
Particularly with the modern trend of developing headers of increasingly larger sizes, providing the capability of a header to follow the contours of the ground is increasingly desirable. One type of prior art leveling mechanism, as can be seen in U.S. Pat. No. 3,981,125, involves the twisting of the feeder house structure about the centerline thereof (i.e. the line of travel of the combine) to effect an associated lateral floating movement of the header. Hillside combines have been developed to allow the header to follow slopes of up to 45 percent. Such hillside combines have been known to utilize a side pivot mechanism as seen in U.S. Pat. No. 3,731,470, and also a center mounted pivot connection directly between the header and the feeder house wherein the connection involves a specific semi-circular opening between the feeder house and the header.
Problems that have been encountered with these prior are lateral float mechanisms include a difficult sealing situation between the feeder house and the base unit as the feeder house is twisted relative to the base unit, and the twisting of the feeder house drive mechanism also increases wear which reduces life in the drive chains. Another problem found in the prior art leveling mechanisms is the matching of different types of headers to different feeder house structures. This problem is particularly relevant to feeder houses having specially shaped crop inlet openings.